PB. Regina #1, Rex-I #10, Rex-I #17, Rex-I #23

PB. Regina #1, Rex-I #10, Rex-I #17, Rex-I #23

Regina #1 Engine-speed-signal missing
Rex-I #17 Engine-speed-signal to Regina missing



Conditions for fault message:
If voltage was no higher than 7.0 Volts during a certain period, the fault message is stored. This period varies with engine speed and is approx. 400 ms at idling and 80 ms above 1200 rpm.

Causes of faults:
Breakage or short circuit to ground in the wire between the control units.
Interference or short circuit in the wires from the impulse sensor. Defective impulse sensor.

Fault symptoms:
Engine does not start.
With intermittent faults, the engine dies or bucks considerably

Rex-I #10 Engine-speed sensor signal missing
Rex-I #23 Engine-speed sensor signal missing



Conditions for fault message:
Engine above 1200 rpm and idle contact off. If voltage has not exceeded 2.5 V during a specific period, approx. 80 ms, the fault message is stored.

Causes of fault:
Breakage or short circuit to ground in the wires from the impulse sensor.
Connection resistance in connections.
Defective impulse sensor.

Fault symptoms:
Engine does not start.
With intermittent faults, the engine cuts out or runs roughly.

PB1




Checking the impulse sensor
- Ignition off.
Connect an ohmmeter between 1 and 2 on the impulse sensor.

Impulse sensor 1 389 567-7 (previous version):
The ohmmeter should show approx. 240 ohms and max. 400 ohms with a hot engine.

Impulse sensor 3 547 847-8 (recent version):
The ohmmeter should show approx. 170 ohms and max. 350 ohms with a hot engine.

If the value Is OK:
^ Disconnection of System Tester PB2.

If the value differs:
^ Test with a new impulse sensor.

PB2

Disconnection of Volvo System Tester
Disconnect the System Tester according to P1. P1. Connection of Volvo System Tester
^ Continue with Connection of measurement box, Rex-I PB3.

PB3




Connection of measurement box, Rex-I
- Connect the measurement box to Rex-I and check chassis connection according to N3-N4. N. Measurement Box, Signal Description
^ Continue with Checking of impulse sensor signal PB4.

PB4




Checking of impulse sensor signal
- Connect control unit to measurement box.
- Insert fuse no.1.
Connect a voltmeter between #10 and #23.
- Operate the starter motor.
The voltmeter should show at least 500 mV (alternating current).

If the value is OK:
1. If fault message Rex #10 or Rex #23:
Intermittent fault.
^ Check the wires between the impulse sensor and control unit for loose connections according to CD. CD. Checking of Wiring
2. If fault message Rex #17 or Regina #1:
^ Checking of engine speed signal PB5.

If the value differs:
^ Check the wires between the impulse sensor and control unit for breakage and short circuit to ground according to CD. CD. Checking of Wiring

PB5




Checking the engine speed signal, Rex-I
Connect a voltmeter between #17 and #20 (ground).
- Operate the starter motor.
The voltmeter should show 7-8 V.

If the value is OK:
1. If fault message Rex #17:
Intermittent fault.
^ Check the wires between the impulse sensor and control unit for loose connection according to CD. CD. Checking of Wiring
2. If fault message Regina #1:
^ Connection of measurement box Regina PB6.

If the value differs:
^ Check the wires between the control units for short circuit to ground according to CD. CD. Checking of Wiring
^ If there Is no short circuit to ground:
^ Test with a new control unit.

PB6




Connection of measurement box, Regina
- Connect measurement box to Regina and check the chassis connections according to N1-N2. N. Measurement Box, Signal Description
^ Continue with Checking of engine speed signal, Regina PB7.

PB7




Checking of engine speed signal, Regina
Connect a voltmeter between #1 and #5 (ground).
- Operate the starter motor.
The voltmeter should show 7-8 V.

If the value Is OK:
Intermittent fault.
^ Check the wires between the impulse sensor and control unit for loose connection according to CD. CD. Checking of Wiring
^ Check the wires between the control units for loose connections according to CD. CD. Checking of Wiring

If the value differs:
^ Check the wire between the control units for breakage according to CD. CD. Checking of Wiring